prioritizing energy savings - spray foam vs. wood stove

[Seasoned Oak]

Drywallers are taught to leave a 1/8 to 1/4" gap between the drywall and plate.

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Whats the purpose for the gap? Expansion??? I always drywall right to the sidewalls ,so the wall sheets can support the top sheets. Iv never had a problem. Usually blow cellulose in tight ,about 3-5 lbs pressurized to prevent settling. Although iv already pushed the drywall away from the wall if i dont have enough screws in yet ,with a good machine. Provides the best wall insulation at the lowest cost. THese new lightweight sheets are so nice! and stronger too.

 

[woodgeek]

That was the way they did it in PA in 1960. I figure it was expansion, but who knows?

Agreed on cellulose. I am thinking of redoing my house exterior, currently 56 yo asbestos concrete shingles, and densepacking the walls at the same time. I **think** they are mostly 1" thick R-3 FG 'econobatts' and several bays are just empty.

 

[maple1]

Let's be empirical....

When I am in my attic, I can look into the gap next to the top plate with a flashlight, and see down 8'.

I'm having a hard time visualizing this. When you are looking down 8', what are you looking at? Are you seeing into the wall cavity? Or into the room below? I can't see how either is possible if the wall gyproc is pushed up against the ceiling gyproc and the joint is taped & mudded. I must be missing something. There is nothing to see there in my attic. The wall & ceiling framing were vapour barriered first, then ceiling & walls gyproced, then the joints taped & mudded.

 

[cableman]

On mine the wall rock was not tight against the top plate so i can shine a light and look into my interior walls. Helped while snaking some wires!

 

[Seasoned Oak]

That was the way they did it in PA in 1960. I figure it was expansion, but who knows?

Agreed on cellulose. I am thinking of redoing my house exterior, currently 56 yo asbestos concrete shingles, and densepacking the walls at the same time. I **think** they are mostly 1" thick R-3 FG 'econobatts' and several bays are just empty.

I just tore out a freezing bathroom that was 3.5 in FG batts in exterior walls. Completely useless! You could feel the breeze coming around the FG. Looked like it shrank too.
Blew the walls tight with cellolose and the ceiling ,now the only heat i need in there regardless of the outside temps, is the infrared bulb fixture i installed in the ceiling,500 watts of drying and heating power. We like it in the 80s while showering.

 

[Highbeam]

On mine the wall rock was not tight against the top plate so i can shine a light and look into my interior walls. Helped while snaking some wires!

Odd but I believe you. Now how did this happen? When you install the wall rock you are setting fasteners into the top plate and the sheetrock is pulled tight to the top plate. Then, you mud and tape the joint. The only way that this gap could happen is if the top plate shrank and the mud/tape joint was so good that the wall rock stuck better to the ceiling rock than it did to the top plate. The fasteners were either pulled out if nails or they ripped through the rock.

None of my top plates have a gap to the wall rock. Maybe our lumber is better. Well, I can no better say that none of mine are gapped than you can say that all of yours are gapped but I can say that wherever I've looked, it's tight.

I agree that if you have this freak problem that you need to fix it.

 

[cableman]

I would say they prolly never nailed to the top plate and it prolly shrank too. Some of the walls have 22.5 angles, u should have seen those gaps! It was actually blowing air on me when i pulled insulation up! I still have a location where i moved a thermastat and need to repair the sheet rock, not one bit of draft through it anymore. I was able to seal up both peak side exterior walls also. That great stuff pro gun is the best! 6 weeks i was in and out of my attics playing twister

 

[blades]

I hate attic work , low attic here, unfortunately I am not particularly small therefore a lousy fit that leaves me feeling like I just got run over by a slow freight. Dreading the repairs I need to do up there - couple quotes were in the $2500 class expense, of which I am about 2300 short. Got to get the code work done at least, the rest will have to wait.

 

[sesmith]

To the OP, you already have 12" of fiberglass so you're close to the recommended R38. It might be a good idea to have an energy audit done with a blower door test to see what might be gained by additional air sealing.

If it were me, I'd do the best I could myself to spot seal any places I could get to in the attic. Then I'd put down additional insulation by blowing in cellulose on top of the fiberglass. Why?? It's cheap. I could do it myself with a big box store rental blower. Cellulose permits much less air flow through it than fiberglass. Then, I'd go down into the cellar and seal the rim joints myself. This is easily done with cut and pieced in XPS sealed in place with spray foam in a can. Pretty cheap and easy to do and little a bit messy.

Then you'd have lots of money left to help with the wood stove install. The stove will likely save you way more propane usage than insulation and air sealing will (unless a blower door test shows otherwise).